Burdwan, April 16: Five more blocks in the district were recently declared arsenic-prone, raising the number of affected zones to seven.
In a joint survey, the State Water Investigation Directorate and the Central Ground Water Board identified Kalna-I, Kalna-II, Katwa-I, Katwa-II and Manteswar as the new areas under threat. Before the survey, two Purbasthali blocks were known to be having toxic groundwater.
Water resources development minister Nandagopal Bhattacharya said four blocks in Kalna and Purbasthali have been declared “dark areas” as the level of arsenic in groundwater was several times more than the safe limit of .05 milligram per litre. Manteswar and the two blocks in Katwa have been marked “grey areas”.
“The directorate investigated the district’s groundwater resources through its hydrographic stations and water samples were tested in its regional laboratories before the declaration was made,” the minister said. Areas where 85 per cent of the groundwater reserves had been exhausted were termed “dark”. Places where the reserves were depleted by 65 to 85 per cent fell in the “grey” zone.
Bhattacharya said over exploitation of the water reserves in the aquifers was resulting in very slow “recharge”. “Moreover, more than 1,62,000 water bodies — ponds, canals and lakes — have silted up. Though the state gets adequate rainfall, the dead water bodies cannot stock water,” said Bhattacharya.
The water resources department is undertaking a project to artificially recharge the underground aquifers, the minister said. “We have launched a pilot project in North 24-Parganas, where river water is being pumped underground during the rains.”
Directorate sources said the results have started coming.